1. Field of the Invention
The present invention relates to an electrosurgical cutting device.
2. Description of the Prior Art
A cutting device of this kind is known through West German Pat. No. 2,504,280. The cutting effect of a cutting electrode results mainly because, at the area where the cutting electrode forms a cutting edge and is applied to the tissue, the tissue is heated intensely in the immediate vicinity of the cutting electrode by the RF current which, among other things, forms arcs so that the cells of the tissue burst, thus resulting in a cut in the tissue. Simultaneously, the protein is coagulated by the heating of the tissue so that the capillary vessels severed during the course of cutting are sealed by the coagulation. An advantage lies in that relatively bloodless cuts can be made with the electrosurgical cutting electrode. If the tissue is heated too intensely, however, in addition to the coagulation of the protein, protein disintegration may result, whereby the consequent healing of the cut is impeded.
For the optimal use of an electrosurgical cutting device, it is therefore important that it be possible to keep the temperature of the cutting electrode precisely at an optimal value.
In order to so set the intensity of the RF current through the automatic and sufficiently quick control operation, so that always the intensity of current exists which guarantees the heating of the tissue suitable for the cutting and coagulation process and, on the other hand, prevents the formation of electric arcs in harmful proportions, it is known through the above-cited West German Pat. No. 2,504,280 to transform the luminous effect of the arc produced between the cutting electrode and the tissue by the RF current into the electric signal of an indication device. This transformation is accomplished with the aid of an opto-electrical transformer, e.g., a photoelectrical cell. It is also known through the same prior art patent to analyze the momentary current of the high frequency circuit with an indication device and to obtain from it electrical signals for the point of application, and/or to analyze the momentary intensity of the arc produced by the RF current. Each of these two measures requires a complex circuit. Moreover, it is not guaranteed that the amount of light absorbed by the opto-electrical transformer or the electrical signals obtained through the analysis of the momentary current of the high-frequency circuit correspond to the temperature during cutting, said temperature being the decisive factor here.